Genetics Flashcards

Flashcards covering key vocabulary terms in genetics.

Gene Regulation

The process of turning genes on and off.

Allelic Interaction

Genetic interactions of the alleles of a single gene.

Gene Interaction

The expression of one gene depends on the presence or absence of another gene.

Haplosufficiency

A single normal allele provides enough function

Haploinsufficiency

A single functional copy of a gene is not sufficient to maintain normal function.

Multiple Alleles

Genes have variations in their nucleotide sequence at several positions.

Lethal Alleles

Gene mutation that can cause the death of an organism, often early in development.

Pleiotropy

A gene affects multiple phenotypic traits.

Epistasis

Expression of one gene is affected by the presence or expression of another gene.

Suppression

A second mutation counteracts or suppresses the effect of an original mutation, restoring the normal phenotype.

Synthetic Lethality

Mutations in two genes together result in cell death, but a mutation in either gene alone does not.

Levene

Long chain made up of subunits he named nucleotides.

Chargaff

Showed that A = T and G = C.

Franklin and Wilkins

Showed that DNA is a helix.

Watson and Crick

Propose that DNA is a Double Helix.

Nucleotide

The subunit of DNA is the nucleotide.

Phosphodiester Bond

Gives the phosphodiester backbone a polarity: 5’ to 3’.

Denaturation

Strands unwind and separated strands with heat.

Renaturation

Double helix reformed.

Hybridization

Combining complementary strands of nucleic acids from different sources to form a hybrid molecule.

Nucleosome

The fundamental unit of chromatin

Chromosome

Condensed and tightly coiled structure formed from chromatin.

Genetics

Studies of how genes and how traits are passed down from one generation to the next.

Heredity

Process by which traits or genetic information are passed down from parents to their offspring.

True Breeding

Always pass down certain traits.

P generation

Parental generation.

F1 generation

First filial generation of a genetic cross.

F2 generation

Second filial generation of a genetic cross.

Reciprocal Crosses

A breeding experiment that reverses the roles of male and female parents in a cross.

Monohybrid Cross

A genetic cross involving a single pair of genes (one trait); parents differ by a single trait.

Segregation

Factors separate during gamete formation.

Testcross

A cross between an organism with a dominant phenotype and a homozygous recessive organism to determine the genotype of the dominant phenotype parent.

Punnett Square

Predict offspring genotypes and phenotypes.

Branch Diagram

Predict offspring genotypes and phenotypes and their relative frequencies from a cross using the multiplication rule of probability.

Multiplication Rule of Probability

Probability of two or more independent events occurring together is calculated by multiplying the probabilities of each event.

Biotechnology

The use of biological systems, living organisms, or their components to develop or create new products.

Recombinant DNA Technology

The joining together of DNA molecules from two different origins.

Vector

A DNA molecule that is used as a vehicle to carry a particular DNA segment into a host cell as part of a cloning or recombinant DNA technique.

Restriction Enzyme

A bacterial protein that cuts DNA at specific recognition sites, generating fragments with either sticky ends or blunt ends.

DNA Ligase

A class of enzymes that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond.

Host Cells

The organisms in which the gene of interest (with or without vector) is inserted and multiplied.

Genetic Engineering

A process that alter the DNA makeup of an organism.

Genome Editing

Refers specifically to the targeted modification of an organism's DNA at a precise location.

Transgenic Animals

Organisms that have had foreign DNA introduced into their genome.

Microinjection

Process of transferring genetic materials into a living cell using glass micropipettes or metal microinjection needles.

Knockout Animals

Animals that have had a specific gene or genes intentionally disabled or knocked out.

Genome Editing

Precise and targeted change to the genome of living cells or organisms.

Polymerase Chain Reaction (PCR)

A technique to make many copies of a specific DNA region in vitro.

DNA Sequencing

A technique for determining the exact sequence of nucleotides, or bases, in a DNA molecule.

Transcription Factor

A protein that controls ability of RNA polymerase to carry out transcription.

General Factors

Factors required by RNA polymerase on all genes.

Gene-Specific Factors

Factors that modulate transcription differently on different genes and in different tissues.

Sex-determining Region Y Gene (SRY Gene)

A key transcription factor that initiates male sex determination and testis development.

Qualitative Traits

Shows discrete, discontinuous phenotypes.

Quantitative Traits

Measured and described in quantitative terms (quantitative inheritance).

Countable (Meristic) traits

Traits that are counted in whole numbers.

Threshold Traits

Traits only expressed in individuals who exceed a certain threshold of genetic or environmental risk factors.

Heritability

Proportion of total phenotypic variance due to genetic variance.

Concordance

When both or neither twins express the trait.

Discordance

When only one twin expresses a trait.

Population

Group of individuals belonging to same species.

Population's Gene Pool

All alleles present in population.

Hardy-Weinberg

Two-allele system, Hardy–Weinberg law application to humans, Analysis of susceptibility to HIV-1 infection.

Allele Frequency

The proportion of a particular allele in a population.

DNA Replication

Process by which a cell duplicates its entire genome prior to cell division.

Dihybrid Cross

A cross between two individuals with two observed traits that are controlled by two distinct genes.

Principle of Independent Assortment

Inheritance of one trait does not affect the inheritance of another.

Pedigree

A family tree diagram that shows the inheritance patterns of a particular trait or genetic disorder across multiple generations.

Codominance

The alleles of a gene pair in a heterozygote are fully expressed.

Incomplete Dominance

The alleles of a gene pair in a heterozygote are partially expressed.

Gene Therapy

The treatment or prevention of disease by replacing a faulty gene, inactivating a malfunctioning gene, or introducing a new or modified gene.

In vivo Gene Therapy

Therapeutic genetic material is delivered directly into a patient's tissues or bloodstream using vectors, without removing cells from the body.

Ex vivo Gene Therapy

Patient-derived cells are genetically modified outside the body and then reintroduced.

Epigenetics

Heritable changes in gene expression that do not involve alterations in the DNA sequence.

Epigenome

The complete set of epigenetic modifications present in a cell at any given time, influencing gene activity and cellular processes.

Epigenetic Trait

Stable phenotype resulting from changes in gene expression, which can be inherited both mitotically and meiotically without changes to the underlying DNA sequence.

Euchromatin

Light stained, less condensed and more easily transcribed.

Heterochromatin

Darkly stained, highly condensed, transcriptionally silent.

Chromatin Remodeling

Rearrangement of chromatin from a condensed state to a transcriptionally accessible state.

Histone Acetylation

Histone acetylation generally activate gene transcription by making DNA more accessible.

Histone Deacetylation

Histone deacetylation represses transcription.

DNA Methylation

DNA methylation typically silences gene expression by preventing transcription factors from binding.

Genomic Imprinting

Process by which only one copy of a gene in an individual is expressed, while the other copy is suppressed.

Linkage

Recombination frequencies will not exceed 50% because of multiple cross-over events.

Genetic maps

Diagrams that show the relative positions of genes on a chromosome based on the frequency of recombination between them.

Deamination

An inherited disease associated with deamination of a base. Removal of an amino group from a molecule.

Base Excision Repair (BER)

Spontaneous deamination of cytosine is the hydrolysis reaction of cytosine into uracil, releasing ammonia in the process.

DNA photolyase

Enzyme to repair a Thymine Dimer Repair: Photoreactivation.

Xeroderma Pigmentosum (XP)

Hereditary condition characterized by extreme sun sensitivity, leading to a very high risk of skin cancer and other medical problems.

Non-homologous End Joining (NHEJ)

Double-strand Break Repair.

Homologous Recombination (HR)

Double-strand Break Repair

Hereditary Breast and Ovarian Cancer Syndrome (HBOC)

Autosomal dominant associated with a BRCA gene.

Operon

Cluster of genes transcribed under the control of a single promoter.

Lac Operon

Operon required for the transport and metabolism of lactose.

Lactose

Sugar that is broken down to release glucose to be used for energy.

Repressor

Repressor is an allosteric protein

CAP protein

Binds the DNA and this makes the promoter a good promoter resulting in lac operon being turned on

Attentuation

Results in lac operon being turn on

Merozygotes"

Diploid for certain added genes

Sex-linked Inheritance

Cells homozygous for genes on mammalian X chromosomes are males, females are heterozygous